Differential axle.



R. C. WETH'ERELL.

DIFFERENTIAL AXLE. APPLICATION FILED NOV-23. l9l5.

1 ,241 ,457q Patented Sept. 25, 1917.

2 SHEETS-SHEET I.

V6222? fiw. (3311M. Mm

R. c. WETHERELL. -D|FF ERENT|AL AXLE.

EAPPLICATION FILED NOV. 23, I915.

1,241,457, 7 PatentedSept. 25,1917.

-2 SHEETS-SHEET 2.

RAYMOND CORDEUX WETHEBELL, 0F SLOUGH, ENG- i DIFFERENTIAL AXLE.

Specification of letters Patent- Patented Sept. 25, 191 7.

Application filed November 23, 1915. Serial Njo. 68,102;

v tractors and the like.

the drawbacks of the ordinary form of differential which drawbacks are evidenced by The object of the invention is to provide means for. allowing the speed of the axle wheels, when on a curve, to differ according to the distance covered by each wheel in the same period of time, and the construction is of that type in which this diflerentiation is obtained by employing a central driving'disk receiving the power, and two independent and laterally immovable side disks attached to the road wheels, the power being transmitted by means of convex, round-ended pins, which slide horizontally through holes in the central driving disk, and engage with concave spherically-surfaced countersunk hollows in the opposed faces of the two indeendent and laterally immovable driven 'sks attached to the road wheels.

The construction is designed to obviate skidding in motor cars when the propeller shaft brake is suddenly applied, and also by the rapid inning of one wheel when it is unable to o tain an adhesion on a slip"- the same with reference to the accompanymg diagrammatic drawings, in which Figure 1 is a sectional elevation of a rear axle casing in which is mounted the new diiierential, parts of which are shown in elevation and others in section.

Fig. 2 is a right hand end view of the female dog clutch member on the left-hand side of a in Fig. 1, which member is lettered f.

Fig. 3 is a right hand view of the parts lettered a, b, m and t in Fig. 1.

Fig. 4 1s a-q'ight hand end view of a female dog clutch member on the right hand side of a, in Fig. 1, which member is lettered f.

Figs. 5, 6 and 7 are external elevations of the new differential showing the relative dispositions of the parts under working formed integrally with or otherwise rigidly attached to it.

The ends of the stub shafts b are shod with'thrust disks t, these being intended to distribute the end thrust which arises from the working of the apparatus and also from the bevel drive.

As will be seen, the stub shafts b are shown provided with keys but they may be castellated as an alternative if desired.

- Upon the shafts b, 6, two peripherally toothed disks or male dog clutclf members are free to slide laterally. These members pery surface, so that the whole of the trac are lettered m, m and are connected to ether tive efi'ort is dissipated in" thisspmmng by means of tie rods 0, c, of the form s own,

wheel, the other wheel remaining stationary the endsbeing riveted into the vmale dogs and acting as a fulcrum for be described are as follows and having shoulders, so that the rods 0 tioned wheel to spin upon. are able to transmit the thrust.

The functions'of the difierentialabout to The rods 0' passfreely throu h apertures in the disk a, without touching t e same.

By this means, the interconnected male the men- When the vehicle enters upon a curve, the

' understood,'I new proceedto de'sc increased speed .ofthe outer wheel causes the inside wheel to be partially or entirely liberated, and to receive none, or only a part of the driving power, the whole or a major portion of the drive being transmitted through the outer wheel, thus assi the steering of the vehicle to which the difierential is fitted.

In all other circumstances, the new differ ential causes the axle to act as a solid axle.

In order that m invention may be clear-11ye dog clutches m, m are able to reciprocate on the keyed stub shafts b, b, while tuming with the disk a.

The foregoing parts .form the primary parts of the differential the secondary parts being as follows The ends of the half axles of the road wheels are provided with hollow cup-shaped members f, f, the stems of the cups..forming hollow bosses, into which the half axle ends are secured.

The usual journal and thrust ball bearings the male dogs m can slidewhen reciprocating along the stub shafts b.

Attention is here drawn to the form of dog teeth employed. It will be noticed that their surfaces are not horizontal, but slope so that in the case of the female dog teeth the opening between the tooth faces is greater on the side towardthe crown bevel dlsk a. Also, the surfaces of the teeth are flat.

The angle-of the male dog clutch tooth face is similarlyarranged with a flat surface, so that when pressure between the male and female dog tooth surfaces is set up, a tendency is created for the male dog to be forced awayfrom the female dog in the direction of the crown bevel disk at. For convenience in description, these male and female dog tooth surfaces are lettered h and g respectively, and it must be also here mentioned that the angle of slope of the dog teeth has been purposely exaggerated to hat would be advisable in practice in order to make the working appear more clear.

The above details can now be condensed or classified into the following two groups 2- The primary group consists of the crown bevel disk a, its stub shafts b, b, thrust disks t, t and sliding male dogs m, m, connected.

together by compression rods 0 0, which prlmary group is held between" the secondary group members consisting of the cupshaped female dog clutch members i, which mesh with the sliding male dogs m, m.

The distance between and also the length of the female dogs are such that the male dogs can slide out of mesh with the female on the one side while the other male dog can enter further into engagement with the female on the other side, as shown in Fig. 7.

The method ofoperation is as follows When the axle is being driven it is assumed that the top of the crown bevel wheel shown in Fig.- 1, is movingin a clockwise direction, when viewed from the right hand side of Fig. 1. This causes the sloping surfaces 9 and h of'the dog teeth to come together as in Fig. 5, and transmit the power to the road wheels.

As long as the axle travels along a straight path, both' wheels turn at the same speed, and consequently boththe sliding dog clutches m, m, attempt to move inward, but

are prevented from so doing by the compression in the rods c, c, the result being that mg m occupgy: their mid position of travel along 6, b.

whe 4 r Now assume that the axle enters on a curve," and thatthe clutch on the left-hand side, of Fig. l is that belonging to the inner 'wheelf The right hand wheel, being on the outside" of the curve, begins to rotate the quicker, therefore causing the contact be-' tween the surfaces 9 and it of the right hand clutch to be momentarily broken as shown 1n Fig.- 6. The result is that the whole of the driving pressure is thrown upon the surfaces 9 and h of the left-hand clutch, belonging to-the inner wheel, with the result ing. at' varying speeds, it'is evident that a certain period must elapse before the teeth of the left-hand clutch are in the proper position to effect this, and in the meantime there Will be a certain amount of friction between the vertical faces in juxta-position of the-left-hand male and female dogs,

which tends to transmit a portion of the drive to the left-hand wheel, this tendency being increased by the act of refneshing when it occurs.

After this, if the wheel is still on a curve, the cycle of operations is continued as before. 1

It should here be mentioned that any convenient number of dog teeth can be employed, the arrangement not necessarily being limited to the four here shown.

'What I claim as my invention and desire to secure by Letters Patent of the United States of America -is:

1. In a differential axle for motor vehicles, the combination of a driving member provided with stub axles, one on each s de thereof, two plates, one located on each side of the driving member, tie .rods connecting together said. plates and passing through appropriate apertures in the driving member, the element constituted by the said plates and the tie rods rotating with the stub axles while being free to move longitudinally with respect thereto, said plates having peripherally arranged teeth, said teeth havin flat inclined surfaces at the sides and p ane surfaces at thev ends, and.

other plates carrying the ordinary half axles, and provided with correspondingly shaped teeth havin inclined surfaces at the sides and plane sur aces at the ends, the last mentioned plates being at such a distance apart that the element constituted by the first mentioned plates and tie rods can slide into such a position that when the teeth on one of the first mentioned plates are fully in engagement with those on the plate in connection with the corresponding axle, those on the other first mentioned plate are entirely disengaged from the other last mentioned plate, for the purposes set forth.

2. In a differential axle for motor vehi cles, the combination of a driving member provided with stub axles, one on each side thereof, thrust disks at the ends of the said axles, two plates, one located on each side of the driving member, tie rods connecting together said plates and passing through appropriate apertures in the driving member, the element constituted by the said plates and the tie rods rotating With the stub axles while being free to move longitudinally with respect thereto, said plates having peripherally arranged teeth, said teeth having flat inclined surfaces at the sides and plane surfaces at the ends, and other plates carrying the ordinary half axles and provided with seatings for the accommodation of the before mentioned thrust disks and with teeth corresponding in shape to those on the plates forming part of the aforesaid element, the last mentioned plates being at such a distance apart that the element constituted by the first mentioned plates and the tie rods can slide into such a position that when the teeth on one of the first mentioned plates are fully in engagement with those on the plate in connection with the corresponding axle, those on the other first mentioned plate are entirely disengaged from the other last mentioned Plate, for the purposes set forth.

teeth having flat inclined surfaces at thesides and plane surfaces at the ends, thrust disks at the ends of the stub axles, and other plates carrying the ordinary half axles and provided with seatings for the accommodation of the before mentioned thrust disks and with female dog teeth corresponding in shape to those on the before mentioned plates, the last mentioned plates being at such a distance apart that the element constituted by the first mentioned plates and the tie rods can slide into such a position that when the teeth on one of the first mentioned plates are fully in engagement with those on the plate in connection with the corresponding axle, those on the other first mentioned plate are entirely disengaged from the other last mentioned plate for the purposes set forth.

In testimony whereof I afix my signature in presence of two witnesses.

RAYMOND G ORDEUX WETHERELL.

Witnesses i A. Browne, L. SIMMONDS. 

